Preparation of wine

ABSTRACT

In a wine making process the skins and pips are separated from the pulp after crushing of the grapes. The pips are removed and the skins are then finely ground in a colloid mill. The ground product is then added to a fermentation must for wind making. The must could be the original pulp or another must.

July 30, 1974 R V NT R ml. 3,826,849

PREPARATION OF wnm Filed May 15, 1973 s MMED GRAPES CRUSHING SEPARATIONPULPY MUST sKms PIPS SEPARATION COLLOID MILL FERMENTAT'ION4'-MUST(PIPQSKIN FREE) SEbIMENT FILTRATION 6 I OR I DECANTATIONY STEMMEDGRAPES CRUSHING ERMENTATION- Bis- I WINE QR PARTIALLY FERMENTED MUSTFILTRATION S s OR COLLOID MILL A TI N WINE SEDIMENT Ser. No. 360,609

Int. Cl. C12g N02 US. Cl. 426- 15 3 Claims ABSTRACT OF THE DISCLOSURE Ina wine making process the skins and pips are separated from the pulpafter crushing of the grapes. The pipsare removed and the skins are thenfinely ground in a colloid mill. The ground product is then added to afermentation must for wine making. The must could be the original pulpor another must.

This application is a continuation-in-part of our patent applicationSer. No. 251,200, filed May 8, 1972, now abandoned.

This invention relates to a process of wine making. In thisspecification the term wine is intended to mean the product made fromgrapes.

Conventionally the first step in wine making is stemming. Here theberries are removed from the stem. The next step is crushing the berriesto break each berry and to expel the pulp from the skin. Depending onthe type of wine to be made, the skins and the pips are separated fromthe pulp or must. For white wines it is conventional to conduct winefermentation on the must without any skins or pips present. For ros winethe skin and pips are present for a portion of the fermentation period.Finally red wine is fermented from a must containing skins and pips. Theskins form a cap on the fermentation mass and the cap has to be immersedinto the fermentation mass by some process such as periodically pushingthe cap down.

Modern industrial techniques are being applied to wine making on anincreasing scale. These techniques such as pumping and the use of closedvessels are more readily applied to the making of white wine as mustcontaining skins cannot readily be pumped and be processed in closedvessels.

With a view to facilitating the handling of the must it has beenproposed in US. Pat. 2,852,387 simultaneously to disintegrate the pulp,skin, pips, and stems in a single operation. Fermentation is thenconducted on this disintegrated mass. However, Ametine et al. in TheTechnology of Wine Making at page 250 characterise the wine as having astemmy taste. They go on to say that for distilling material thedisintegrator is undoubtedly of great utility.

The applicants have found that with total disintegration there is also aputrid or rancid taste which is due to the oil contained in the pips.

At best wine made from totally disintegrated grape bunches is of aninferior quality and the method of total disintegration cannot be usedfor quality wines.

An object of the invention is to provide a wine of a better qualitycompared to wines made from the same raw materials while at the sametime, at least in some embodiments, the must is easier to handle.

According to the invention a wine making process, in which grape berriesare stemmed, crushed after stemming to liberate the pulp and the pulp isfermented in the presence of grape skins, is characterised in that grapeskins and pips are separated from the pulp, the skins United StatesPatent 3,825,849 Patented July 30, 1974 ICC and pips are separated fromone another, the pip-free skins are finely comminuted, the comminutedskins are added to a pulp to form a suspension, and the suspension isfermented to make wine.

Preferably the skins are comminuted in a colloid mill. In the result theskin particles have a maximum diameter of 1 millimetre or less andpreferably of between 0.1 and 1 millimetre.

The invention is further discussed with reference to the accompanyingdrawings, in which:

FIG. 1 is a flow sheet of one process according to the invention, and IFIG. 2 is a flow sheet of an alternative process.

In FIG. 1 stemmed grape berries are first crushed in a conventional wayto free the pulp from the skins. Next the skins and pips are separatedfrom the pulp, as for white wine making. The pulp that remains is usedfor making wine on its own or it may be the must that is introducedlater on in the process illustrated in FIG. 1.

The pips are next removed from the skins. Up to now the inventors havenot encountered a satisfactory way of mechanically separating skins frompips in the freshly crushed state. Of necessity in the process of FIG. 1the separation must be by hand. The inventors have successfully usedhand separation through holed screens. This process being labourintensive is only suitable for highly priced Wines.

The pip-free skins are then passed through a colloid mill whichcomminutes them very finely.

The ground product is then mixed with a suitable must, which may be theoriginal pulp from which the skins came or another pulp. The mixture issubjected to controlled fermentation. The mixed product can be handledlike any white wine pulp and fermentation can be conducted in closedfermentation vessels. While a cap in the accepted sense of the word isnot formed, some of the skin particles tend to float to the top andthese should be recirculated.

Since there is no pumping problem, pumps could be used to draw materialfrom the top and reintroduce it to the base of a vessel or the other wayround.

The fermentation product is treated in the usual way to provide wine anda sediment as a waste product.

Sometimes the sediment could be used with another quantity of must toprepare some more wine.

A number of experiments utilising the process of FIG. 1 have beencarried out. These experiments were not quantitative. However, in eachcase it was found that the quality of the wine produced was better thanthat of wine produced in a conventional manner from the same rawmaterial. Except for the difiiculty of separating skins and pips thematerial handled much easier than in conventional red wine makingprocesses. Of course, not only red wine was made.

To obviate the difiiculties with pip and skin separation the process ofFIG. 2 was devised. In this process the grapes are crushed and the mustfermented in the usual way. After fermentation the skins and pips areseparated from the wine. Now the skins and pips can be separated byutilising conventional machinery such as the Garolla depipper.

'Fhe fermentation need not be complete before the Garolla depipper canwork. A partial fermentation is sufficient.

In the process of FIG. 2 a conventional first class wine may first bemade. Then the skins are used after passing through the colloid mill toproduce a lesser grade wine, but even then the latter has been found byorganoleptic tests to be better than that conventionally produced fromthe same must.

It is also possible to conduct the fermentation partially and then toseparate the skins and pips from the must.

After passing through a depipper and colloid mill the skins are returnedto their source and fermentation continued EXPERIMENT During the 1973wine season in South Africa relatively low quality grapes of theHermitage variety were produced by the vineyards. The harvest had a weakcolour, light red instead of black, and was low in sugar content: 19.5B. to 21.5 B. as compared to 22 B. to 26 B. during other seasons.

A portion of the Hermitage grapes going into a winery from a crusher wasdiverted and subjected to a special treatment as follows. The must,including skins and pips, was fermented until the sugar content reachedabout 12 B. in a conventional red wine making vat. The sap was thenwithdrawn and the remaining mass of skins and pips passed through aGarolla depipper. The skins mixed with some sap were ground in a colloidmill and returned to the main body of sap. Fermentation was allowed tocontinue until the sugar content was 0 B. The latter step took place ina closed vessel and the sap was withdrawn at the base and pumped intothe top on top of the rising skin particles.

The finished wine and solid residues were then separated in the usualway.

In the experiment 131,190 kg. of crushed grapes were used and thisproduced 129,335 litres of wine. The production of wine per kg. ofgrapes were exceptionally high.

The fresh wine was submitted to three wine experts. They pronounced thecolour very good in the light of the bad raw material. Furthermore theypronounced the flavour and aroma better than that obtained in normalyears from the Hermitage variety of grapes. They rated the quality 15 to20% higher than usual. One expert predicted that the wine produced bythe experiment would be ready for the market within six months. NormallyHermitage wines have to age at least 18 months before they are releasedto the market.

The large scale experiment conducted according to the FIG. 2 embodimenthas thus confirmed the small scale "4 experiments conducted with theFIG. 1 embodiment. The applicant believes that the quality of wineproduced from almost any grape variety can be improved by the processesof the invention. The stemmy taste of total disintegration is avoidedand the rancid taste that sometimes results from fermentation in thepresence of pips is also avoided.

What is claimed is:

1. A wine making process in which grape berries are stemmed, crushedafter stemming to liberate the pulp, the crushed pulp, skins and pipsare first partially fermented, the skins and pips are separated from thepulp, the skins and pips are separated from one another, the skins arefinely comminuted, the finely commuted skins are added back to thepartially fermented pulp, and the suspension of partially fermented pulpand comminuted skins is fermented to make wine. a

2. A wine making process in which grape berries are stemmed, crushedafter stemming to liberate the pulp, the skins and pips are separatedfrom the pulp, the skins and pips are separated from one another, theskins are finely comminuted, the finely comminuted skins are added to askin and pip free pulp to form a suspension and the suspension isfermented to make wine.

3. The process claimed in claim 2 in which the finely comminuted skinsare added back to the pulp from which they were originally derived.

References Cited UNITED STATES PATENTS 9/1958 Minetti 99-35 OTHERREFERENCES DAVID M. NAFF, Primary Examiner US. Cl. X.R. 426-484

